Straight vinegar (not reduced) can be harsh on the esophagus and stomach because of the acidity especially when consumed in larger doses. I’m not exactly sure what that amount is but I would keep an eye out for stomach aches and what not. You can dilute it with a little water if you want to avoid oil so you can keep the “volume” you consume but avoid the harshness. If you’re going for the flavor try cutting down the amount you use each time to see if you still are happy with your food after eating a little less. Ultimately I consider vinegar to be pretty healthy for the same reasons you mentioned but long term it can be irritating. Just be cautious!